1. Field of the Invention
The present invention relates to an information medium apparatus and an information medium starting method for recording or reproducing information on or from an information medium by using a light beam from a light source such as a laser. Particularly, this invention relates to an information medium apparatus and an information medium starting method for selecting one light source from a plurality of light sources such as a blue laser, a red laser and an infrared laser, and performing an start processing procedure corresponding to the selected light source.
2. Description of the Related Art
Conventionally, a method described in Japanese Laid-Open Publication No. 2000-90440 is known as a method for determining a type of an optical disc. In this method, a lens is moved between a position where the lens is closest to the optical disc and a position where the lens is sufficiently far from the optical disc. During the movement process, it is determined whether or not there is light reflecting from a surface of the optical disc, and whether or not there is light reflecting from a signal surface of the optical disc. In this way, the type of the optical disc is determined. In this method, the position where the lens is closest to the optical disc is a position where the lens is in contact with the optical disc.
However, the optical disc apparatus described in Japanese Laid-Open Publication No. 2000-90440 has the following problem. Since the closest position is the position where the lens is in contact with the optical disc, the lens and the optical disc bump into one another when the lens is moved between the position where the lens is closest to the optical disc and the position where the lens is sufficiently far from the optical disc, although the bumping is marginal. Thus, an optical disc may be damaged in the worst case and it may become impossible to be record or reproduce information to or from the optical disc. Furthermore, when a blue laser is used to irradiate an existing optical disc, which is recorded or reproduced by using a red laser or infrared laser, such as a DVD disc or a CD disc, recorded data may be destroyed.